The dynamics of diachronous extinction associated with climatic deterioration near the neogene/quaternary boundary
The dynamics of diachronous extinction associated with climatic deterioration near the neogene/quaternary boundary
To predict extinction, we must understand the processes leading to terminal population decline. Once a critical threshold of population size is reached, small environmental perturbations can push a species over the cliff-edge to extinction, so the main drivers of extinction are the factors that cause the initial reduction in population size. Most studies of population decline leading up to extinction focus on modern species in a human-dominated world. The drivers of population decline leading to non-human mediated extinctions are less well known but changes in climate are arguably the most widely invoked mechanism. Here, we report data on >16,000 individuals of the planktonic foraminifer Globoconella puncticulata from six sites in the Atlantic Ocean along an 83 degree-long latitudinal transect, over a 600,000-years interval leading up to the species’ global extinction during the late Pliocene-earliest Pleistocene intensification of Northern Hemisphere glaciation. We show changes in geographic range, abundance, and body size. We find that populations do not follow a North-to-South sequence in extinction as Earth cooled and developed large ice sheets in the high latitudes of the Northern Hemisphere. Instead, our results suggest that (a) populations are differentially adapted to local environmental conditions such as nutrient availability, (b) population dynamics in core populations differ from those at the edge of their range, and (c) individual population responses to external pressures are essential to understanding the drivers of global extinction. Our study demonstrates the potential to transform our understanding of extinction dynamics through spatially replicated sampling of the highly resolved marine microfossil record.
Northern Hemisphere glaciation, Pliocene, biogeographic range contraction, extinction, planktonic foraminifera, pre-extinction dwarfing
Brombacher, Anieke
2a4bbb84-4743-4a36-973b-4ad2bf743154
Wilson, Paul
f940a9f0-fa5a-4a64-9061-f0794bfbf7c6
Bailey, Ian
e659068f-e591-4185-afd1-5e19a5794bda
Ezard, Thomas
a143a893-07d0-4673-a2dd-cea2cd7e1374
2 June 2021
Brombacher, Anieke
2a4bbb84-4743-4a36-973b-4ad2bf743154
Wilson, Paul
f940a9f0-fa5a-4a64-9061-f0794bfbf7c6
Bailey, Ian
e659068f-e591-4185-afd1-5e19a5794bda
Ezard, Thomas
a143a893-07d0-4673-a2dd-cea2cd7e1374
Brombacher, Anieke, Wilson, Paul, Bailey, Ian and Ezard, Thomas
(2021)
The dynamics of diachronous extinction associated with climatic deterioration near the neogene/quaternary boundary.
Paleoceanography and Paleoclimatology, 36 (6), [e2020PA004205].
(doi:10.1029/2020PA004205).
Abstract
To predict extinction, we must understand the processes leading to terminal population decline. Once a critical threshold of population size is reached, small environmental perturbations can push a species over the cliff-edge to extinction, so the main drivers of extinction are the factors that cause the initial reduction in population size. Most studies of population decline leading up to extinction focus on modern species in a human-dominated world. The drivers of population decline leading to non-human mediated extinctions are less well known but changes in climate are arguably the most widely invoked mechanism. Here, we report data on >16,000 individuals of the planktonic foraminifer Globoconella puncticulata from six sites in the Atlantic Ocean along an 83 degree-long latitudinal transect, over a 600,000-years interval leading up to the species’ global extinction during the late Pliocene-earliest Pleistocene intensification of Northern Hemisphere glaciation. We show changes in geographic range, abundance, and body size. We find that populations do not follow a North-to-South sequence in extinction as Earth cooled and developed large ice sheets in the high latitudes of the Northern Hemisphere. Instead, our results suggest that (a) populations are differentially adapted to local environmental conditions such as nutrient availability, (b) population dynamics in core populations differ from those at the edge of their range, and (c) individual population responses to external pressures are essential to understanding the drivers of global extinction. Our study demonstrates the potential to transform our understanding of extinction dynamics through spatially replicated sampling of the highly resolved marine microfossil record.
Text
Brombacher et al., accepted
- Accepted Manuscript
More information
Accepted/In Press date: 24 May 2021
e-pub ahead of print date: 2 June 2021
Published date: 2 June 2021
Additional Information:
Funding Information:
Samples were provided by the Integrated Ocean Drilling Program (IODP), which is sponsored by the US National Science Foundation and participating countries under management of Joint Oceanographic Institutions, Inc. We thank Walter Hale and Alex Wuebers for their kind assistance during visits to the Bremen IODP Core Repository. A. Brombacher acknowledges a Johanna M. Resig Fellowship awarded by the Cushman Foundation. T. H. G. Ezard was funded by NE/J018163/1 and NE/P019269/1. P. A. Wilson acknowledges funding from a Royal Society Wolfson Merit Award. We thank Laia Alegret, Manuel Weinkauf, and an anonymous reviewer for insightful and constructive comments that improved the manuscript.
Publisher Copyright:
© 2021. The Authors.
Keywords:
Northern Hemisphere glaciation, Pliocene, biogeographic range contraction, extinction, planktonic foraminifera, pre-extinction dwarfing
Identifiers
Local EPrints ID: 449651
URI: http://eprints.soton.ac.uk/id/eprint/449651
ISSN: 2572-4525
PURE UUID: 30b836dc-b209-4ab4-b214-0ecd9e01422c
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Date deposited: 10 Jun 2021 16:31
Last modified: 17 Mar 2024 03:48
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Author:
Ian Bailey
Author:
Thomas Ezard
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